Means for controlling solenoid brakes



Sept. 23, 192-1.

B. C. JACOB MEANS FOR CONTROLLING SOLENOID BRAKES Filed Nov. 25, 1922 Patented Sept. 23, 1924.

UNITED STATES BRENT C. JACOB, OF CLEVELAND, OHIO, ASSIGNOR TO THE BROWN CHINERY COMPANY, OF CLEVELAND, OHIO, A CORPORATION.

1,509,210 PATENT OFFICE.

HOISTING MA- MEANS FOR CONTROLLING SOLENOID BRAKES.

Application filed November 25, 1922 Serial No. 603,294.

To all whom it may concern:

Be it known that I, BRENT C. JACOB, a citizen of the United States, residing at Cleveland. in the county of Cuyahoga and State of Ohio, have invented a new and use-- ful Means for Controlling Solenoid Brakes, of which the following is a specification.

The invention relates more particularly to the class of mechanisms that are employed for retarding and stopping the man trolleys of overhead hoisting and conveying machines, wherein the mechanism for the purpose is actuated by solenoid effects upon and in opposition to a spring or other force, and, the improvement now introduced has for its object, generally speaking, such an arrangement of parts with relation to the electrical circuits prescribed, that the motor shaft may be controlled, as to all regular service requirementsfby what isknown as low or service torque, with a reserve of high to us braking-force, however, constantly available for emergency, or other exceptional conditions.

In arranging for this object, therefore, the invention takes into account and remedies the inconveniences and undesirable accompaniments that characterize the opera tion of machines as now made. whether such machines are positively provided with braking facilities, or rely entirely upon the method of stopping the trolley, by reversmg the motor, commonly referred to as plugging. In the former case. the traversing motor is equipped with a. solenoid-brake, and as such brakes and pertaining circuits are now arranged, if'stopped thereby, the stopping will be so abrupt as to unduly jar the operator and rack the machinery and parts. If the stops in such cases, are made by plugging, instead of by the solenoidbrake provided, in order to succeed, the controller handle must be passed so quickly over the off position in the movement to reverse the motor current, that the solenoidspring will not always be given time to function and set the brake. On this account, in practice, it is found that the attempt to stop trolleys by plugging, instead of by using their solenoid brakes, requires too fine a manipulation of the controller to be depended upon, and, also, that in such use, as well as where the trolley is not provided with any positive braking equipment, although the trolley itself is gradually stopped thereby, the bucket is not, but will continue to swing, and often with suflicient force to carry the trolley beyond the intended halting point or station.

Having in view these deficiencies in the art concerned, the present improvement, as indicated, so corelates the wires and electrical equipment of a solenoid-brake for mantrolleys, with the mechanical parts involved, that the trolley can be slowed down and brought to a stop at any point of its travel, without jar, of undue strains.

In the drawings Figure I is a. side view of a solenoid-brake unit with its brake shoes in contact with a brake-wheel mounted on a motor-shaft, and, Figure II is a diagram of a system of electrical wiring for the various circuits that enterinto and contribute to the invention claimed.

Like parts and components are designated by the same reference characters in each case.

MS is the motor or armature shaft of the motor M.

BWV is the brake-wheel, keyed to the motor shaft MS.

S, S are brake-shoes adapted to embrace the brake-wheel BW.

L, L are brake-levers, that support the shoes, S, S at L, L.

ELI; is the plunger-core of an electro-magnet E is the stationary-core or stop of the electro-magnet EM.

A connecting rod R projects into a mortise in the upper end of the core E, where it is pivotally fastened, and extends upwardly to a distance approximately that of the levers L L. The rod 'is. provided near its upper end with a spring-cap G and at its upper end with a clevis K. A springP, preferably under an initial compression, is threaded on the rod R and occupies the space between the cap C and the frame F, of the electro-magnet EM.

Pivotally fastened to the clevis K, between its prongs, is a fulcrum-link FL which is also pivotally connected to the lever L at L".

rod PR of the T-shaped plunger-switch PS. The plunger-rod is provided, intermediate of its ends, with a collar PC, which is integral with the same and which stops or limits the travel of the-plunger-rod into the core E. The collar also affords a seat for the plunger-switch spring SS.

A U-shaped spring-support and plunger guide U, with a hole in the bottom thereof toreceive the plunger-rod PR, is fastened on the bottom of the magnet-frame F. The spring SS, preferably under an initial compression, extends from the bottom of the spring-support U to the collar PC on the rod PR. 7

A contact-piece CP, of the T-shaped plunger-switch PS, projects from each side of the rod far enough to span or bridge the gap between Wire-terminals W and W.

CD is a development of the controllerdrum showing the relation of the drum segments at, b, c, d, e, f, g, h, i and on the forward side of the drum and a b c d e f g 70, h and j on the reverse side of the drum with the steps or notches 1, 2, 3, 4, 5, and 1, 2, 3 4, 5", and, the contact fingers m, n, 0, 72,1, 8, t, u, 'v, w, and m.

The main or supply circuit, comprising the positive'supply main PM and the negative supply main NM, is represented by the letters SC. v

6, 7 8 and 9 are resistances in the motor circuit by which the speed of the motor is regulated.

10 and 11 are resistances in the solenoid circuit by which the flow of current through the electromagnet is governed. These, in every case, are of course to be duly proportioned to the results and purposes for which they are introduced.

12, 12 are the connections for the motor armature winding.

13 is the motor field-winding.

14 is a solenoid that actuates a contactorswitch 15.

16 and 17 are contactor-switch terminals.

' 18 is the driving pinion on the motorgear on the intermediate shaft.

A wire 26 connects the contact-finger it A wire 34 connects the contact-finger 'w with the wire 32. v

A wire 35 connects the contact-finger m with the positive supply main PM.

A wire 36 connects a switch-terminal 37 with'the positive supply main PM.

A wire 38 connects a switch-terminal 39 with a solenoid winding terminal 40 of the solenoid EM. 1

A switch is adapted to close the gap between the terminals 37 and 39 and thereby permit current to flow from the supply mains through the system of circuits involved for their normal operations. When in this relation the switch may be made to serve as a means for setting an emergency brake, as occasion requires, by simply throwing it back to its open position, whereby all power to the solenoid brake coil will be shut-oil, and the compression springP of course be freed to instantly set the brake at the maximum torque.

A wire 42 connects a solenoid windingterminal 43 to the resistance 11.-

A wire 44 connects the resistance 10 with the negative supply main NM of the supply circuit SC.

A wire 45 connects the contactor-terminal 17 with the wire 42.

A wire or conductor 50 connects the segments a, b, 0, d, e and f.

A wire or conductor 51 connects the segments 9 and h.

A wire or conductor 52 connects the segments 5 and y.

A wire 53 connects the segments a, b, a, d, e and f.

A wire 54 connects the segments g' and k. t

A wire 55 connects the segments in and j.

' and the spring P,

A wire 56 connects the wire 25 with the wire 26.

Normally, when the trolley is idle, the controller handle will, of course be on the oil position, and the switclr4l, and contactor 15, open. The solenoid EM, in consequence, will be Without magnetic energy, be free to exert its full expansive force upon the braking mechanism and thereby set the motor brake to the emergency torque.

In order to travel the trolley under these conditions, the normal pressure of the spring P, is first to be partially overcome to a degree that will reduce the braking force to the service torque desired. This is brought about by throwing in the switch 41, whereupon current will flow at the same time over the main core-magnetizing circuit 3644, and the branch, or normally closed, subsidiary circuit that comprises the elements and the wire sections 47, terminals W, the intermediate plungerswitch PS, the wire 48, the wiring around the solenoid 14, the sections 49, to 44.

Thereupon, the normally open loop, or branch circuit, madeup of the conductors 45, 17, 15, 16, and 46, will be thrown in whereby the resistance 11 will be cut out and the main current, now flowing over conductors 36, 37,41, 39, 38, 40, the winding of the solenoid EM, 43, 42, 45, 17, 15, 16, 46, 25, the resistance 10, and the wire 44, to the negative supply main NM, will short-circuit the resistance 11, and current will flow through the solenoid coil EM, but, because of the calculated resistance 10, at a rate that will cause the ger E, against the s ring P, to so overalance an absolute raking force, as to enable the trolley to be either gradually stopped, or held and operated at a prede-v termined service torque.

When the brakes are set at the low torque referred to, and it is desired to release the same and start the trolley, the controller handle is thrown over one notch, whereupon for the fraction of the instant until the core E has encountered and moved the plunger-rod PR downwardly towards the spring SS, both resistances 10 and 11, will be cut out, and, in consequence, the core E will be magnetized by the full force of the current. This insures a quick release of the brake from the maximum expansive force of the s ring. During this infinitesimal interva, however, the current will follow a shunt circuit to the negative main NM, over the contactor 15, wires 16, 46, 25, 56, 26, the controller elements a, b, 50, a, m, and wire 21. When, however, the core is thus pulled down to the stationary core, or sto 'E", less current will be required to hold t e spring than was required to compress it to that degree and POlIliJ, therepull on the plunfore, it is possible to reduce the current ac cordingly. This'is done again by throwing in the resistance 11.

Provision to this end is furnished by the plunger-switch PS, its upwardly extending rod PR, the collar PC. and spring SS in the seat U, as hereiubctore described. The plunger-rod is of suitable length when car; ried upwardly through the core E by the force of the spring, to bring the switch PS into contact with the wire terminals \V and W',"and to project through the core E, to be encountered by the core E in its downward course. The rod will thereby be depressed against the spring SS until the switch PS is opened and current to the solenoid 14 demagnetized in this manner, the current, that before went over the circuit 4546, will follow the circuit that extends from the solenoid EM, over 43, 42, through the resistance 11, over the sections 25, 56, and 26, through the controller elements to 21 and the negative main N11.

In order to stop the motor on a service torque, rather than abruptly on the exnergency torque by the full enpansive force ot the spring, the trolley should be slowed down and the controller handle thrown to the off position. Thereupon the solenoid circuit 3621 will be interrupted, and, until the core E has been brought away from the plunger-rod PR, current will flow from the positive supply main PM, over 36, 37, 41, 39, 38, 40, the solenoid winding of EM, 43, 42, resistance 11, 25. resistance 10, 44, to the negative main NM. 9

By thus directing the current through the resistances 10 and 11, by reason of the reduced supply of current to the elect-ro-magrnet. EM, a quick separation of the cores E r and E is insured, but, because, at the instant of such separation. under the influence of the spring SS. the plunger-rod PR will close the switch PS which, in turn, will close the contactor switch 15. and the spring P will thereafter be held by the current over the original circuit 36-44, at the decree of compression for the service torque designed.

Although, as a specific and illustrative form of the improvement covered by this application. I have shown a definite manner of co-relating the circuits involved and other concrete details. such as a spring, for instance, rather than a counterweight or other means for automatically actuating the braking mechanism. or. the particular kind of braking mechanism itself. it is to be under stood that I do not intend to limit the invention, asbroadly claimed, to such forms and details but desire to cover all variations that Widen the same to the full meaning of the language used.

at is claimed as new and sought to be protected by Letters Patent, is

broken. The solenoid 14 becoming 1. In combination, with mechanism for settin the brakes of power shafts when actuate by the expansive force of a compression spring, a solenoid having its core operatively related to said mechanism in opposition to said spring, and a system of (0- related electrical circuits comprisin a main circuit for energizing said solenoi having resistance therein, a subsidiary circuit for reducing said resistance, provided with a contactor-switch, a subsidiary circuit for closing said contactor-switch, and 2. normally-open shunting circuit for cutting out remaining resistance, together with means for closing said shunting circuit, substan= tially as shown and described.

2.1n combination with mechanism for setting the brakes of power shafts when said mechanism is actuated by' a freely actin force applied for the purpose, a solenoid having a core .operatively related to said mechanism in opposition to said force, and a system of co-related electrical circuits for energizing the solenoid to the degrees severally required to retract the core in the direction of said opposition and thereby reduce the braking force from an emergency to a predetermined service torque, said system comprising a main circuit for energizing the solenoid with resistances therein, a normally-open loop circuit, auxiliary to the main circuit, embracing a predetermined portion of said resistances, and containing contactor-means for closing said loop circuit when actuated for the purpose, a normallyclosed branch circuit in shunt with the main circuit, provided with means for opening, the same and having a solenoid operatively related to said contactor-means, and means for closing said normally-closed circuit when said means for opening the same is idle, substantially as described.

' BRENT C. JACOB.

Witnesses:

- L. P. LIPPS,

E. K. MrLLER. 

